Wire Rope.

Paper read by Mr. Wm. Henry Wallace, before the Mechanics' Club of the American Institute, Wednesday Evening, April 23d, 1856.

As society has advanced in knowledge, and men have become more familiar with the natural mineral resources at their command, attention has been given to their fullest development; and thus we find there is a steady, yet progressive action continually going on to supplant the vegetable by the use of the mineral. And nowhere will this be found more general than in the application of iron in our times, to almost all conceivable purposes. It is not alone left for railroads, steam-ships, telegraphs, and naval armaments to consume this valuable product, but in these parts at least, we draw largely from it for our dwellings, ware-houses, public buildings, railroad station, &c., and each year as we advance in our experience, the demand becomes greater, until we are most ready to accept the proposition of a great English writer and political economist, that the civilization of a community is in direct proportion to its consumption of iron.

I leave these general ideas, however, to dwell more particularly, through briefly, on iron as manufactured into ropes, and purpose showing some of its advantages in this application.

Rigging. -- As shipping generally furnishes the greatest market for the consumption of rope, I will endeavor to compare the wire rope with the hempen, and show some points wherein I conceive lies its superiority for this purpose.

You will please note, I refer entirely in this paper to standing, not running rigging. One advantage I will proceed to say, is, that wire ropes of equal strength with hempen, are but one fourth part as bulky; from which I argue, that the sailing qualities of the vessel must be improved just in the proportion that the surface exposed against the wind is decreased. For example, the main stay on a steamer of 3,000 tons, if made of hemp rope, would require to be 12½ inches in circumference, whereas, if made of wire rope, the size of same stay would be decreased to only 5 inches circumference. This advantage would be appreciated on a vessel having auxiliary steam-power when making way against the wind.

Another advantageous feature, and of still more importance, is the great economy in weight, being about fifty per cent. less. The standing rigging of a steam vessel of the same size as before, 3,000 tons, from her shrouds and stays on her lower mast, including those of top-mast, top-gallant-masts, royal masts, and jib gear, would weigh, if made of hemp rope, 12.74 tons, while if made of wire rope, and same strength, the weight would be reduced to 8.24 tons, leaving a saving in favor of the wire rope of 4.50 tons; and in a sailing ship of 1,300 tons the saving in weight would be about the same. This large saving in weight, when it is remembered that the average of th[e] standing rigging is placed above the centre of buoyance, must naturally increase the stability, and particularly the steadiness of a ship. And this comparison will hold good in smaller classed vessels, as in an 80 ton yacht, the saving would be about .50 of a ton.

Another point I would offer in its favor, but one however, in my experience with nautical gentlemen, I find there is an unusual difference of opinion, is that while some maintain the greater elasticity the better, others hold that the less elastic the rigging, the better display the vessel has for her sailing qualities.

This question, I think, has been clearly settled in favor of the latter, in the published experiments made by Messrs. Newal & Co., of London, where well seasoned hemp, and wire shrouds, of equivalent strengths, under strains equal to one-third that which would break them, or more than they are usually exposed to. These experiments show that while the stretch or permanent lengthening of the wire rigging is nothing compared with that of hemp, difference in springiness is not more than one inch in favor of hemp in the longest shrouds; practically, therefore, the less elasticity of wire rope can be of no importance. All again, by the use of turnbuckle-screws at the end of shrouds and stays, in place of lanyards and dead eyes, the slacking or tightening is accomplished with much greater facility and readiness, saving thereby a great deal of labor.

It has sometimes been suggested by those who have not given due reflection, whether there was not more danger from lightning in using wire rope than hemp. Now, whereas, if the bulwark irons holding the shrouds are extended to the copper, every wire shroud will become a lightning conductor, as may also be the case with the stays, so that the vessel is rendered perfectly proof against lightning.

For our naval vessels especially, wire rope is decidedly preferable, not more on account of its greater safety from fire than from the enemy's shot and these two points alone are of sufficient importance to call for a careful consideration of the subject on the part of our Naval Bureau of Construction. Here our English friends are in advance of us; its introduction having been made in the Royal Navy, over fifteen years ago, and its adoption steadily followed both in the Navy and by the mercantile marine service, down to the present time. The steamers "Bosporous"; "Himalaya", "Parana", "Oronoco", Bengal", "Simba", "Arato", "Emu", and "Tersia", being among the last having more or less of their standing-rigging of wire rope.

I will take the liberty of reading to you an extract from a paper read by Mr. Andrew Smith, before the Mechanical Section of the British Association for the Advancement of Science, at St. George's Hall, Liverpool, in September, 1854.

"In the year 1848, the British Navy had in commission, 376 ships of every class. The expense for hempen rope standing-rigging for the above number of ships, (hempen rope being at the rate of about £ 40 per ton,) amounted to £ 114,330. In consequence of wire rope being more than twice as strong for the same weight of hempen rope, the cost for the standing rigging of the above number of ships, made of wire rope, amounted to about £ 86,000, thus showing a saving of about £ 28,000, for one outfit of the Royal Navy; at that time wire rope was £ 60 per ton".

As there are now more than double the number of ships in commission and the price of hempen rope is also doubled £ per ton, the cost to the country for an outfit of standing hempen rigging would be £ 914,640.

Wire rope, on the contrary, is reduced to £ 40 per ton, instead of £ 60, as in 1848. The use, therefore, of wire rope instead of hempen, would effect a saving, in one outfit for the whole Navy, of £ 157,320.

Beyond this the wire rope is much more durable. Speaking from the experience of twenty years, it may be taken as three times more durable; in fact, unlike hemp, the older the wire is the stronger it gets. Several ships in the Royal Navy, have been fitted from 15 to 16 years with this rope, and it is now as good as when first put over the mast-head. Hempen rope in the Royal Navy, is fitted every three years, or every time the ships are put in commission. In the port of Liverpool a great number of vessels have been fitted with this rope in about 15 years; consequently, if it is admitted to be three times more lasting or durable than hempen rope, there would be a saving effected in three commissions, or nine years, for the standing rigging of the Royal Navy, of £ 1,371,960.

As enormous as the aggregate saving may appear when the comparison is applied to the Royal Navy, I will venture the assertion, that an equally economical pro rata result will be arrived at when the comparison is made with our own Navy -- and I regret that I have not been able, in the brief and periodical leisure I have had to devote in preparing this paper, to obtain data and make the comparison.

The foregoing, however, will answer the present purpose of showing the economy of the wire rope, in the point of wear.

Here, however, the difference in cost between the hemp and wire rope would not be so great. The great disparity in England being, I suppose, partially attributable to the late war with Russia. Again, wire rope, unlike hempen rope, is not affected by the sudden changes of temperature: as in a northern climate, where tarred rigging gets hard, unyielding, and brittle, or under tropical sun, where the tarred rigging becomes soft and flows, giving thereby great annoyance. Neither is it liable to those sudden changes in length, to which hemp rope is subject, and which, as every sailor knows, gives rise to inconvenience, and great labor in setting up the rigging, and to serious accidents, when, as often happens, the change takes place in a single night, in circumstances that render it impossible to set up the rigging before trouble has ensued.

I have endeavored at some length to call your attention to this field for the application of wire rope, not only because the great bulk of ropes manufactured are for this purpose, nor alone from the fact its advantages are so numerous and well sustained abroad; but because its manufacture in this country is of modern date, and its introduction for vessels standing rigging not yet made, or so limited only, as not to be generally known.

However, when it shall have become developed by our own experience in the mercantile aud [sic] naval marine service of this country, as I feel assured it soon must, its advantages will be as equally appreciated here, as they now are with our friends across the Atlantic, and its application be as common.

Bridges. -- . . .

Manufacture. -- I will close this paper by briefly describing the powers of its manufacture, which, like the production of many other similarly valuable commodities, is simple, yet combining with much ingenuity, and a great deal of well arranged machinery.

The iron, first of all, should be of the very best quality.

The bars are first heated to a welding heat, then passed a number of times through a train of three rolls, running at a velocity of about 500 revolutions per minute, reducing the iron down from 1 1/8 inch in diameter to about 1/4 of an inch.

Then scaled or cleaned by being placed in warm water with a little sulphuric acid or vitrol mixed, afterwards coated with a preparation of leece or paste made of rye flour, and one end being filed down, passed through a thick drawing plate containing a series of conical shaped holes, and drawn down to No. 5 thickness of wire gauge, which is about the limit of reduction it will sustain, until softened. The process of annealing next takes place, occupying from 5 to 8 hours, and then another course of cleaning and drawing. The number of times this is repeated, depending on the fineness of wire required; for very fine wire it may be half a dozen times.

The wires now being prepared for use, next comes the laying from them of the strands, and finally, the laying of the strands into rope.

Each strand usually consists of 3, 7, or 19 wires, the ropes having 9.49, or 133 wires.

The two most important considerations to be effected in laying up the rope are, that when the rope is made and subjected to its duty, that the tension of each wire shall be equal, and that there shall no twist take place in the wires while being laid into strands, nor in the strands while being laid into the rope.

The first is effected by a simple mechanism of weights suspended, one at the end of each wire passing over pullies, and are slackened as the strand is forming, and the weights drawn up, and the same is the case with regard to the strands, the weights being proportionally increased.

The latter requires more machinery but very ingeniously arranged, (and which is patented by the manufacturer) being no less than a continual revolving of each wire, while the strand is being formed, and also of each strand while the rope is being laid -- a striking and peculiar feature in this arrangements is, that it enables the centre strand to be similar to the others, of wire, instead of using hemp, so that where rigid ropes are required, as in standing rigging, the strength is very materially increased.

The foregoing, I hope, may give a general idea of the process of making, but a correct knowledge of the machinery could hardly be mparted, unless by observation when in operation.

To the ends of wire rope when required, can be attached a socket, hook-clevice, turnbuckle, or any similar appendage, in a perfectly secure and safe manner.

The ropes may also be easily spliced, &c., &c.

The U.S. Nautical Magazine, and Naval Journal. Vol. IV (1855). pp 192-197.

Transcribed by Lars Bruzelius

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Copyright © 1996 Lars Bruzelius.